Electric brake for automobiles



Aug. 8, 1933. H. JOHNSON Er A1.

yELECTRIC BRAKE FOR AUTOMOBILES ginal Filed Oct. 25, 1927 2 Sheets-Sheet l R. fw 0 V.. E MN N o NSE T .INN T. HL A No@ mm ,N E HLB ug. 8,*1933-l 'I H JQl-.lNsoN Er AL Re. 18,9172

ELECTRIC BRAKE FOR AUTOMUBILES f origihalyiled odi. ze, 1927 2 sheets-sheet 2 INVENTOR.' HAROLD JovmsoNv LENNlE O. AUNE.

55549. zgn

l ATToR Y UNITED STATES 18,912 V 1 ELECTRIC BRAKE F OR AUTOMOBILES- Harold Johnson, Windom, and Lenm'e 0.-,Aune,

deceased, late of Windom,

Minn., by Albert B.

Welles, assignee, lMinneapolis, Minn., assignor to Bendix kBrake CompamzSouth Bendylnd.,

a Corporation of tion for reissue 462,386

Illinois original No. 1,691,812, dated Serial No. 228,906, October June 19,11930. Serial No.-

November 13, 1928, 26, 1927. ,Applicas claims. (el. 18s-163) This invention relates to an electric brake `for motor vehicles and the like, the general-object of the invention being to provide magnetic means for expanding the brake bands witha switch for controlling the circuit of the magnetic means, such switch being so constructed that the amount of current passing to the magnetic means is regulated by the pressure exerted upon the switch arm. Another object of` the invention is to so arrange the band expanding members that a single magnetic means will operate the same. This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to Abe hereinafter fully described, illustrated in the accompanying drawings and specically pointed out in the appended claims.

In describing our invention in detail, refer ence will be had to the accompanying drawings wherein like characters denote like or corresponding partsthroughout the several views, and in whichz- Figure 1 is a diagrammatic side elevationv of an automobile, showing the invention in use;

Figure 2- is an elevation of the brake assembly of a wheel, with parts in section.A f

Figure 3 is a section through the switch member.

Figure 4 is a section on line 4 4 of Figure 3. Figure 5 is a sectional view through the magnetic means.

In these views, 1 indicatesa drum which forms part of the wheel of a Vehicle and 2 indicates a 35 pair of brake bands having the usual linings 3 thereon for engaging the inner circumference of the drum'to prevent or check movement of the wheel. Each band is yieldinglysupported at its center through means of a bracket 4 attached to the center of the band'and receiving a stationary rod ,5, a` spring 6 being placed in each bracket and bearing against the closed` end. thereof and against the rod so that the spring tends to hold the band out of engagement with the drum. /A pair of internally threaded members 7 is pivotally connected with each band or shoe, one adjacent each end thereof and a rod 8 has its threaded 4end engaging each member 7, a nut 9 locking the parts in .adjusted pos'ition.v each pivoted to a projection 11 carried -by the axle and the bent inner ends of these levers are pivoted to the twol lower rods 8. A bar 12 has a threaded rod 13 pivoted to each end thereof and the outer end of each lever 10 is pivoted to a threaded rod 14 and each rod 14 is'connected `From the" foregoing it will be seen Two levers 10 areV with a rod 13` by an` internally threaded sleeve 15. The central part of the bar 12 is pivoted to the innerends of the upper bars 8. 1

The magnetic means comprises an 'upper coil i6 and a lower coil 17, the lower coil having a core 18 which extends into the bore of the upper coil, the upper coil being providedawith a central pro- `ection 19 which is adapted to extend into a socket-20 formed in the core and this member 19 has a central passage 21 so Lthat aircan escape 65 from the socket 20 as the coremoves upwardly into the upper coil 16 Conductors 22 connect each coil with a terminal 23 and conductors 24 connect each coil 'with a terminal 25. The 'terminal 23-is connected by a conductor 26 with a 70 vbattery B and connector 27 connects a terminal 25'with' a terminal 28 arranged vat the bottom of a combined switch .and resistor casing 29 which contains a plurality of carbon disks 30, the lower one of which is in contact with terminal 28. The

cover 31 of the switch casing carries aterminal 32, which is connected by a conductor33 with the second terminal of the battery B. Both casing l 29 and cover 31 are, of course, .of insulating material. cover and has a part 35 of conducting material,

and insulated from the `body -of Vthe bell crank,

extending through a hole in the cover sothat'this part will engage the upperV carbon disk 30 when the switch arm is in operative position. The85 switch arm lhas a conducting strip 36 fastened thereto for engaging the terminal32. 'Ifhis arm is connected by a link 37 with a foot pedal 38. that when Vthe foot pedal is depressed, the arm tilted from the dotted .line position to the full line position shown in Figure 3 and thus the circuit to the magnetic means will be closed by the strip 36 coming in contact with the terminal 32. The current will pass from the battery to the terminal 32 and through the strip 36 and projection 35 of the switch arm vthrough the carbon disks to the terminal v281mm which it will pass to the magnetic means through the conductor 27 and from `such means it will return to the battery over the conductor 26. Thus the magnetic means will be energized so that the lower coil will ,be raised and this movement of the lower coil will be transmitted to the bar 12 so that the upper adjustable members will press the u'pper portions of the shoes '105' against the drum 1 and at the ame time the levers 10 will be moved `on their pivots 11 through meansol the adjustable connections between the levers and the bar 12 so that the lower adjustable members will i'orce the lower portions of the shoes 110 A bell crank switch arm 34 is pivoted to the 80 34 Will be 90 this arrangement eliminatessbrake rods, springs against the drum. Thus the shoes will be pressed against the drum 1 of the wheel andthis lpressure is regulated by the force withwhich the pedal is depressed, as the greater the pressure 'of the switch arm on the carbon disks, the greater will be the amount of current passing through the magnetic means. Thus the operator can apply his brakes lightly to simply check the vehicle or he can apply them with great force to bring the vehicle to a stop.4 Aswill be seen, the parts'are adjustable so that the brakes `can be adjusted very easily andJ quickly and' it will also be seen that and the'like. Weprefer to operate each brake on a separate circuit so that if the wires leading to one break should be damaged, the brakes of the other wheels will still operate.

It is thought from the foregoing description that the advantages and novel features of our invention will be readily apparent.

It is to be understood that we may make changes in the construction and in the combination and arrangement of lthe several parts, provided that such changeslfall within the scope of the appended claims.

What we claim is- 1. A brake of the class described comprising a pair of shoes for engaging the part to be braked,

' magnetic means comprising an upper coil and a lower coil and an armature connected with theA lower coil and passing into the upper coil, adjustable means' for causing the movement of the lower coil to pressthe shoes against the said part, a circuit for the two coils, ya switch, including an operating arm, in the circuit; manually operated means for operating the switch, such means corncomprising a pedal, a link connecting the pedal to the switch karm andV said switch comprising a casing, a plurality of pieces of carbon therein and a switch arm having a part engaging the pieces for pressing them together when the pedal is depressed.

2. Brake mechanism comprising, in combination, a rotor to be braked, a friction device operable to absorb the kinetic energy of said rotor, magnetic means operable to actuate said friction dev ice, a normally open` circuit including said magnetic means, said circuit also including a combinedswitch and -carbon pile resistor mech'- t anism, together withmeans for closing said circuit. f

- 3. Brake mechanism comprising, in combination, a rotor to be braked, a friction device operable to absorb vthe kinetic energy of said rotor,

magnetic means operable to actuate said friction' l device, a normally open circuit including said magnetic means, "said circuit also including' a combined switch andresistor, a plurality of conductor elements within the resistor together with a manually operable lever means for actuating said switch to-close the circuit', thereby energizing said magnetic means, said means being operative to progressively and selectively compress the elements of the resistor to thereby vary the degree of energization of the magnetic operatingmeans.

4. Brake mechanism comprising brakes, an electriccircuit, magnetic means in said circuit to actuate said brakes, and manually operable control means for said circuit, said last mentionedl means including a variable pressure responsivel rheostat whereby any. minute variation in the manual effort exerted proportionately varies the strength of the magnetic means actuating said brakes.

5. In combination with an automotive'vehicle, brakes, a power source, a power transmitting connection between the brakes and the power source including a compressible power transmission device responsive to increased compression to increase the power being transmitted and manually operable mechanism for producing varying compression in said power transmission device. v 6. An internal expanding brake structure comprising a plurality of shoe members and means each of the said -friction members to simulta-` neously exert brake applying pressure adjacent each end of the friction means.

8. Brake mechanism including, in combination, a pair of arcuate friction members 'iloatingly supported at their mid portion, means normally yieldably urging each of said friction means radially inwardly, a single element coupled with said friction means, said coupling including means for exerting pressure radially outwardly against each end of each friction means, and a power unit supported within said friction means coupled with said element, said power unit being adapted to automatically exert pressure in a release direction upon deenergization thereof.

9'. In combination with an automotive vehicle, brakes, a power source, connections between the brakes and Ysaid power source, a pedal, a power varying device including means to yieldably react against the pedal effort in proportion to said pedal effort and the power transmitted, and connections between said power varying device and the pedal.

" HAROLD JOHNSON,

ALBERT B. WELLES, Assignee of Lenne O. Auna, Deceased. 

